Theoretically AM broadcasting should be capable of a 5k bandwidth. I think back in the '30s and '40s, compression was achieved by manually, (and I would say expertly), manipulating the level on the fly so that the result was a sensation of hearing the full dynamic range of the program. The producer, with a score, would guide the engineer to anticipate a loud entry by gradually reducing the level so the change isn't noticeable but then the sudden loud passage carries the full impact. Automatic gain control could never match this effect. This, of course, was developed when AM was the format of the day. Balancing for 78 rpm discs required a similar procedure. 

db

Sent from my iPhone

> On Sep 28, 2015, at 9:37 PM, Tom Fine <[log in to unmask]> wrote:
> 
> AM must have been something very different back then. I can't imagine ANY music, much less symphonic music over the typical AM radio station today. My cellphone has better fidelity than the nearly non-understandable palaver broadcast by the talk-radio stations in NYC these days. WCBS, Newsradio 88 is often so crunched and distorted, and confined to about 1000 hz of frequency bandwidth, that I can't understand it in my car unless I am parked on a quiet street and listen very carefully. I've transferred oral history tapes made by a recorder placed across an echo-y kitchen that sound clearer. Their webcast signal is actually slightly more audible than what goes over-air, but notice how everything is distorted and super-compressed, and full of digital artifacts, yuk!.
> http://player.radio.com/listen/station/wcbs-newsradio-880
> 
> -- Tom Fine
> 
> ----- Original Message ----- From: "Mark Durenberger" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, September 28, 2015 9:28 PM
> Subject: Re: [ARSCLIST] a piece of Minneapolis Symphony and Mercury Records history
> 
> 
>> WCCO was an AM station, so, single-mike mono.  I recall a pretty nice fight when I asked Master Control to disable the CBS (tube-type) Audimax during the concert.  WCCO's 50 kilowatt big stick allowed for a good deal of quieting so we got away with it <g>.
>> 
>> 
>> Regards,
>> 
>> Mark Durenberger
>> 
>> -----Original Message----- From: Tom Fine
>> Sent: Monday, September 28, 2015 4:47 PM
>> To: [log in to unmask]
>> Subject: Re: [ARSCLIST] a piece of Minneapolis Symphony and Mercury Records history
>> 
>> Hi Mark:
>> 
>> First of, kewl story about the broadcast audio. So you set up 1-mic mono pickup, or 3-mic stereo?
>> 
>> Also, you are spot-on about Collins. I found a photo of the one Mercury recording session in
>> Louisville in 1950. That mixer and those early Ampex 300 machines were used there, too. And there's
>> a front view of the mixer, showing the Collins insignia. I think that mixer was used in the first
>> iteration of the recording van, feeding the two Fairchild machines. The Fairchilds, by the way,
>> theoretically would print less audible scrape-flutter because the tape path was a loop around the
>> heads with rolling guides on each side of the loop (thus less length of "string" to vibrate between
>> the roller and heads).
>> 
>> -- Tom Fine
>> 
>> ----- Original Message ----- From: "Mark Durenberger" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Monday, September 28, 2015 3:53 PM
>> Subject: Re: [ARSCLIST] a piece of Minneapolis Symphony and Mercury Records history
>> 
>> 
>>> ...And now that I blow up that photo it seems those are the original fader knobs; sorry...
>>> 
>>> 
>>> Regards,
>>> 
>>> Mark Durenberger
>>> 
>>> -----Original Message----- From: Mark Durenberger
>>> Sent: Monday, September 28, 2015 2:50 PM
>>> To: Association for Recorded Sound Discussion List
>>> Subject: Re: [ARSCLIST] a piece of Minneapolis Symphony and Mercury Records history
>>> 
>>> Mixer is almost certainly a Collins.  But it has RCA fader knobs (known for
>>> better tactile feedback).
>>> 
>>> Shortly after Tom's Dad established the miking for that room I was fortunate
>>> to do one of the first live MSO remote broadcasts for WCCO Radio, using
>>> CRF's mike technique...and a mixer by RCA (OP-6/OP-7 series).
>>> 
>>> It was a "thrill" getting up into the catwalk to hang that broadcast mike
>>> (an Altec IIRC).
>>> 
>>> 
>>> Regards,
>>> 
>>> Mark Durenberger
>>> 
>>> -----Original Message----- From: Tom Fine
>>> Sent: Monday, September 28, 2015 1:14 PM
>>> To: [log in to unmask]
>>> Subject: [ARSCLIST] a piece of Minneapolis Symphony and Mercury Records
>>> history
>>> 
>>> A long-time MLP fan tipped me off to this photo being for sale on eBay. I
>>> jumped right on it!
>>> https://dl.dropboxusercontent.com/u/55748706/Minneapolis%20Tribute%20520120%20First%20MLP%20session.jpg
>>> 
>>> this is from the very first Mercury recording session in Minneapolis,
>>> January 19-20, 1952. Dorati
>>> made his first recordings of Borodin's 2nd, Stravinsky's compete "Firebird",
>>> Berlioz "Roman
>>> Carnival" and pieces by Ravel and Debussy. The tape machines shown are
>>> "portable" Ampex 300's (they
>>> still weighed about 100lbs each, whether or not in portable cases). David
>>> Hall is using what I think
>>> is a Gates portable mixer/mic preamp (it might be RCA or Collins). The
>>> recordings were made with a
>>> single Neumann U-47, and the
>>> Gates unit probably was used to provide a gain stage after the mic and to
>>> distribute the signal to
>>> both tape recorders. David Hall is probably working with Dorati and the
>>> assistant conductor to
>>> gather approved takes he can edit together. The next time Mercury visited
>>> Minneapolis, fall 1952, my
>>> father had built his recording truck.
>>> 
>>> -- Tom Fine
>>